Cars and boats, the wiring is commonly traced as accessories are added, and I always use color coded wire.

Houses? Well, I haven't found a good supply of color coded romex, but I do spray the inside of each junction box with a separate color of paint to represent different circuits.. Who knew that the computer, microwave and refrigerator would be on the same circuit?( I have a 70 yr old house now )

Basically, if you are going to wire it, and never touch it again, I wouldn't bother with color coding.. Trailers are not that complex in their wiring.. You might have 2 circuits in there.

...you should be able to run everything except your mains in 12/14 ga wire(I am using 14) your mains should be at least 8/10 ga(I am using 8 ). If you run a common ground it should also be 8/10 ga
madjack

p.s. if you are going to use an inverter, the circuit it is on should also be 8/10ga depending on size of inverter

...I have come to believe that, conflict resolution, through violence, is never acceptable.....................mj

On the AC side, I'm using chopped up 3 conductor extension cord 14ga. The wires are color coded inside.

On the DC side I'm using 2 conductor red/black 14ga or 16ga depending on load. The main connection between the inverter and battery is 4ga, the connection from the battery to power distribution block is 8ga.